Charles herbert smith



Patented Ian. 3. I899.

No. 6I6,980.

c. H. SMITH. alcvcua FORK cnown.

(Application filed July 17, 1897.)

(No Model.)

NITED STATES PATENT Fries.

CHARLES HERBERT SMITH, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE GEO. L. THOMPSON MANUFACTURING COMPANY, OF SAME PLACE.

BICYCLE FORK-CROWN.

SPECIFICATION forming part of Letters Patent No. 616,980, dated January 3, 1899.

Application filed July 17,1897. Serial No. 644,881. (No model.)

To ctlZ whom it may concern:

Be it known that I, GHARLEs HERBERT SMITH, of Chicago, in the county of Cook and State of Illinois, have invented certain new 7 and useful Improvements in Bicycle Fork- Orowns; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, and to the letters of reference marked thereon, which form a part of this specification.

This invention relates to an improved construction in fork-crowns for bicycles and in the process of making or forming the same from sheet metal.

The invention consists in the matters hereinafter described, and pointed out in the appended claims.

The invention may be more readily understood by the accompanying drawings, in which- Figure 1 is a View in front elevation of a front-fork crown constructed in accordance with my invention. Fig. 2 is a side elevation thereof. Fig. 3 is a central vertical section thereof, taken on line 3 3 of Fig. 2. Fig. tis a vertical cross-section thereof, taken on line 4 4 of Fig. 3. Fig. 5 is a view in front elevation of one of the parts or sections constituting one-half of the crown, the same being shown when straight or before being bent into curved form. Fig. 6 is an end view of the part shown in Fig. 5. Figs. 7 and 8 are views in side elevation of the inner and outer faces of the fork-crown section when in the shape shown in Fig. 5. Fig. 9 shows a drawn tube or thimble from which the sections are made.

In its general shape a fork-crown embodying my invention is like the similar crowns heretofore used, the same being of curved or semicircular form and adapted for attachment to the fork-spindle at its top. The crown con sists of two similar tubular parts or sections A A, which are joined to each other or welded together along the line a a at the top and center of the crown, Figs. 1 and 3, and which is provided at its top with a collar or tubular flange a, which forms a circular opening or socket, in which the lower end of the forkspindle is inserted and secured. Said collar is surrounded by an outwardly-extending half of the crown and one ofthe fork-arms.

The section may, however, be made separate from the fork-arm and adapted for attachmentto the same. Such construction is shown by dotted lines in Fig. 1, in which the section is provided at its lower end with a reduced part a, adapted to enter the upper end of the fork-arm, and to which the latter is secured by brazing in the usual manner. In the upper end of each section (and at the side of the section which when the article is finished is uppermost or at the top of the crown) is formed a half-collar or semicylindric flange 0 the same being so arranged that when the two sections are joined end to end the half-collars will constitute the collar 0. at the top of the crown. The edges of the metal constituting the halfcollars are bent outwardly to form semicircu lar flanges M, which together constitute the annular flange a In the upper end of each section,opposite the half-collars,is also formed a notch or semicircular recess a which,with the corresponding recess in the other section, forms the opening a Said half-collars a are formed from the sheet metal constituting the end portions of the tubular sections by bending, forging, or swaging the sheet metal in such shape as to form semicircular openings and at the same time to form the collars referred to, the metal which constitutes the collars being that which is bent outwardly in making such semicircular openings.

In Figs. 5, 6, 7, and 8 I have shown one side of the sections constituting the crown as it would appear after being drawn into tubular form and having a lateral semicircular collard and semicircular flange a. formed thereon, but before it is welded or joined to its companion section. As will be clearly seen from these figures, the drawn tube constituting the section is shaped at its upper end to form at one end of its flattened sides the half-collar of and opening a when the tube is still straight, the end portions of the tube between said half-collar and opening being flattened or spread to form the front and rear parts a a which when the parts are joined constitute the central portion of the crown.

The two parts, made in the shape illustrated in Figs. 5 to 8, may be bent into curved form and then joined by electric welding, or they may be first joined and the straight tube formed thereby thereafter bent into semicircular shape. This latter process is illustrated by the dotted lines B B, Fig. 3, which lines illustrate the position of the tubular sections or thimbles after being joined and before being bent into curved form. By the electric welding process it becomes possible to easily make a welded joint between the abutting edges of the opposite side pieces a a of the tubes, an operation which would be exceedingly difficult, if not commercially impracticable, by the usual welding process.

Fig. 9 illustrates a straight tube which is prepared from sheet metal by the use of ordinary drawing-tools and from which one of the sections is formed. Said tube is made thicker at its upper than at its lower end, thereby giving the necessary quantity of metal at such upper end for the formation of the meeting edges and flanges and to give sufficient strength to the finished article.

The metal at the extremity of the drawn tube between the half collars a and openings, which is bent or swaged to form the two flat transverse side pieces a a is provided with straight edges a a", which edges are made of uniform thickness and are adapted to abut against each other when the sections are placed together. The making of the said edges a of uniform thickness is of importance, for the reason that in the electric welding process it is found that a variation in the thickness of the metal at the welding-point produces inequality of heating effect, due, probably, to the varying conductivity of different parts of the edges when made of varying thickness. The practical effect of a variation of thickness is shown in the burning out of the thinner part of the edge instead of a uniform heating of the entire edges, such as occurs when the parts are of uniform thickness and therefore of uniform conductivity.

As far as the formation of the tubular parts or sections composing the crown is concerned, the same may be made by the employment of any suitable or usual tools adapted for first drawing the tube and then swaging, shaping, or forging the parts thereof to bring the same into the desired shape.

The principal advantages gained by the employment of the construction and processes described are that the fork-crown thereby produced may be constructed quickly and one piece or continuous with the fork-arm's or fork sides, as herein shown, the fork-arms are made from. drawn tubing, which is-prepared in pieces of sufficient length and made thicker at one end than the other to give sufficient thickness of metal to form the crown.

I claim as my invention- 1. A bicycle fork-crown having curved tubular arms and a central collar at its top, said crown consisting of two drawn-metal tubular sections of curved shape, each having a laterally-projecting half-collar at its end; said sections being joined end to end with the side margin of the half-collars together by means of a vertical, welded joint at the center of the crown arranged transversely of the adjacent ends of the sections.

2. A bicycle fork-crown having curved tubular arms and a central collar at its top, said crown consisting of two drawn-metal tubular sections of curved shape which are thicker at their inner than at their outer ends, each having a laterally-projecting half-collar at its end, said sections being joined end to end with the side margins of the half-collars together by means of a vertical, welded joint at the center of the crown arranged transversely of the adjacent ends of the sections.

3. A bicycle fork-crown having curved tubular arms and a central collar at its top, said crown consisting of two drawn-metal tubular sections of curved shape, each having a laterally-projecting half-collar at its upper end, which half-collar is provided with an outwardly extending flange arranged in a plane parallel with the axis of the adjacent end of the section, said sections being joined end to end with the side margins of the halfcollar together by a vertical, welded joint located at the center of the crown arranged transversely of the adjacent ends of the sections.

4. A fork for bicycles consisting of integral fork-arms and a crown, the same being formed of two tubular sections which are curved at their upper ends to constitute the crown, said sections each having a laterally-projecting half-collar at its upper end, and the sections being joined end to end with the side margins of the half-collars together by a vertical, welded joint at the center of the crown arranged transversely of the adjacent ends of the sections.

In testimony that I claim the foregoing as my invention I affix my signature, in presence of two witnesses, this 25th day of J unc, A. D. 1897.

CHARLES HERBERT SMITH.

lVitn esses:

O. CLARENCE POOLE, WILLIAM L. HALL. 

